JP2008177495A - Method and apparatus for processing substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for processing a substrate capable of preferably drying the substrate surface at low cost when drying a substrate surface wet with a processing liquid. <P>SOLUTION: Rinse liquid adhered on the substrate surface Wf is substituted by the liquid mixture by supplying a liquid mixture (IPA+DIW) to the substrate surface Wf after a rinsing process. Thereby, the rinse liquid adhered in a gap between patterns FP formed on the substrate surface Wf is substituted by the liquid mixture. Subsequently, a paddle-like liquid layer 21 of DIW is formed on the substrate surface Wf by supplying DIW from a mist supply nozzle 9 as a mist to the substrate surface Wf. Thereby, the liquid mixture in the surface layer portion is removed from the substrate surface Wf in a state with the liquid mixture entered inside the gap of the patterns FP substantially remaining. Thereafter, the liquid layer 21 is removed from the substrate surface Wf for drying the substrate surface Wf. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for drying a substrate surface wet with a processing liquid. The substrates to be dried include semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, A magneto-optical disk substrate is included.

  A number of drying methods have been proposed in the past to remove the rinse liquid adhering to the substrate surface after the chemical liquid treatment with the chemical liquid and the rinse treatment with pure water or the like. As one of them, a drying method using a liquid (low surface tension solvent) containing an organic solvent component such as IPA (isopropyl alcohol) having a surface tension lower than that of pure water is known. As this drying method, for example, there is a drying method described in Patent Document 1. A substrate processing apparatus that executes this drying method is an apparatus that spin-drys a substrate that has been subjected to chemical treatment and rinsing. In this apparatus, IPA mixed pure water obtained by mixing IPA and pure water after chemical treatment is supplied to a substrate surface from a two-fluid mixing nozzle together with nitrogen gas to perform a rinsing process. This removes chemicals and particles adhering to the substrate surface and suppresses the generation of watermarks on the substrate surface during the drying process.

  Further, in the substrate processing apparatus described in Patent Document 2, after performing development processing on the substrate surface on which the resist pattern is formed, an IPA aqueous solution in which IPA and pure water are mixed is supplied as a rinsing liquid to the substrate surface. is doing. Thereby, the rinse process by IPA aqueous solution is performed with respect to the substrate surface. Subsequently, the substrate is subjected to heat treatment to remove the rinse liquid from the substrate surface. In this manner, the substrate surface is dried while preventing the resist pattern from collapsing by executing the rinsing process with the IPA aqueous solution.

JP 2003-168668 A (FIG. 6) JP-A-7-122485 (FIG. 4)

  However, in the substrate processing apparatus described in Patent Document 1, IPA mixed pure water is supplied to the substrate surface as a rinsing solution after the chemical treatment, and the chemical solution and particles adhering to the substrate surface are removed. The substrate processing apparatus described in Patent Document 2 also uses the IPA aqueous solution as a rinsing liquid after the development process to remove the resist after the development process and the developer remaining on the substrate surface. For this reason, a corresponding rinsing time is required to remove the processing liquid (chemical solution or developer) and unnecessary substances adhering to the substrate surface, and the consumption of IPA increases. As a result, a large amount of IPA is required to process the substrate, which has been one of the main causes of cost increase.

  Further, a liquid (low surface tension solvent) containing IPA or the like whose surface tension is lower than that of pure water contains not a few particles (nonvolatile components). Therefore, when a liquid containing IPA or the like is supplied before the substrate surface is dried, particles contained in the liquid accumulate on the substrate, which may cause a problem that the substrate surface is contaminated.

  This invention is made in view of the said subject, and provides the substrate processing method and substrate processing apparatus which can dry a substrate surface favorably at low cost when drying the substrate surface wet with the processing liquid. With the goal.

  A first aspect of the substrate processing method according to the present invention is a substrate processing method for drying a substrate surface wetted with a processing solution, and in order to achieve the above object, a low surface tension solvent having a surface tension lower than that of the processing solution is used. A substitution step of supplying the surface of the substrate held in a substantially horizontal position and replacing the treatment liquid adhering to the substrate surface with a low surface tension solvent; a liquid having the same composition as the treatment liquid or a treatment liquid and a main component A liquid layer forming step for forming a paddle-like liquid layer on the substrate surface by supplying the same liquid to the substrate surface after the replacement step, and a drying step for removing the liquid layer from the substrate surface and drying the substrate surface In the liquid layer forming step, the liquid is supplied to the substrate surface in the form of a mist.

  According to a first aspect of the substrate processing apparatus of the present invention, in order to achieve the above object, the substrate holding means for holding the substrate in a substantially horizontal posture with the substrate surface wet with the processing liquid facing upward, and the processing A replacement means for supplying a low surface tension solvent having a lower surface tension than the liquid to the substrate surface and replacing the treatment liquid adhering to the substrate surface with the low surface tension solvent; and a liquid or a treatment liquid having the same composition as the treatment liquid And a first liquid layer forming means for supplying a liquid having the same main component to the surface of the substrate on which the low surface tension solvent is adhered in a mist form to form a paddle-like liquid layer of the liquid on the substrate surface, The liquid layer is removed from the substrate surface and the substrate surface is dried.

  According to the first aspect of the invention (substrate processing method and apparatus) configured as described above, the processing liquid adhering to the substrate surface is transferred to a low surface tension solvent (hereinafter simply referred to as “a surface tension solvent”) having a lower surface tension than the processing liquid. Therefore, even if a fine pattern is formed on the surface of the substrate, the low surface tension solvent can enter the pattern gap. Then, a liquid having the same composition as the treatment liquid or a liquid having the same main component as the treatment liquid is supplied to the substrate surface to which the low surface tension solvent is adhered, and a paddle-like liquid layer is formed on the substrate surface. As a result, it is possible to suppress the low surface tension solvent entering the pattern gap from coming out of the pattern gap to the surface layer portion. In addition, most of the low surface tension solvent on the surface of the substrate, that is, the low surface tension solvent in the surface layer portion is removed from the substrate surface while leaving only the low surface tension solvent existing in the pattern gap by the formation of the liquid layer. Therefore, the problems as described in the section “Problems to be Solved by the Invention” can be solved. That is, it is possible to prevent the substrate surface from being contaminated by particles present in the low surface tension solvent. Furthermore, in order to allow the low surface tension solvent to enter the inside of the pattern gap, a low surface tension solvent that only replaces the treatment liquid adhering to the substrate surface may be supplied to the substrate surface. The liquid layer is formed of a liquid different from the low surface tension solvent without using the low surface tension solvent. Therefore, it is possible to reduce the cost by suppressing the consumption of the low surface tension solvent required for processing per substrate.

  Moreover, according to the present invention, since the mist-like liquid is supplied to the substrate surface when the paddle-like liquid layer is formed, the following excellent effects can be obtained. That is, when a paddle-like liquid layer is simply formed on the substrate surface, it is conceivable that a nozzle is fixedly disposed above the substrate surface, and liquid is discharged from the nozzle in a columnar shape and supplied to the substrate surface. However, when the liquid is supplied to the surface of the substrate in this way, the flow velocity of the liquid at the surface portion (hereinafter referred to as “direct supply portion”) located directly under the nozzle and receiving the liquid supply directly from the nozzle is directly supplied. As the liquid spreads from the site, the liquid flow rate at the surface site (hereinafter referred to as “indirect supply site”) that receives the liquid supply indirectly increases. As a result, the low surface tension solvent that has entered the pattern gap located directly at the supply site is replaced with the liquid for forming the liquid layer. As a result, when the substrate surface is dried, there is a possibility that the pattern located directly on the supply site collapses. On the other hand, according to the present invention, since the mist-like liquid is used when forming the paddle-like liquid layer, the flow velocity of the liquid reaching each part of the substrate surface can be made relatively small. For this reason, it can suppress that the low surface tension solvent which has entered the inside of the pattern gap is replaced with the liquid for forming the liquid layer. Accordingly, since the substrate surface is dried from the state where the low surface tension solvent remains in the pattern gap, the pattern collapse can be prevented and the substrate surface can be satisfactorily dried.

  Here, when forming the paddle-like liquid layer, a mist-like liquid may be supplied to the substrate surface from a fixed nozzle fixedly arranged above the substrate surface, or along the substrate surface. The movable nozzle may be configured to scan the substrate surface while locally supplying a mist-like liquid to the substrate surface from a movable nozzle that is movably disposed. Regardless of which configuration is used, a paddle-like liquid layer is formed on the substrate surface using a mist-like liquid, so that the low surface tension solvent entering the pattern gap forms a liquid layer. It is possible to reliably prevent the liquid from being replaced. Further, according to the former configuration, it is not necessary to drive and control the nozzle during the liquid layer forming process. On the other hand, according to the latter configuration, it is possible to prevent the mist-like liquid from being scattered around the substrate by locally supplying the mist-like liquid to the substrate surface.

  According to a second aspect of the substrate processing method of the present invention, there is provided a substrate processing method for drying a substrate surface wet with a processing liquid, and a low surface tension solvent having a surface tension lower than that of the processing liquid is used to achieve the above object. A replacement step of supplying the surface of the substrate held in a substantially horizontal posture and replacing the processing liquid adhering to the substrate surface with a low surface tension solvent; and a liquid or processing liquid having the same composition as the processing liquid after the replacement step; A liquid layer forming step for supplying a liquid having the same main component to the substrate surface to form a paddle-like liquid layer on the substrate surface, and drying for removing the liquid layer from the substrate surface and drying the substrate surface In the liquid layer forming step, the nozzle is scanned with respect to the substrate surface while supplying the liquid in a columnar shape from the nozzle.

  According to a second aspect of the substrate processing apparatus of the present invention, in order to achieve the above object, the substrate holding means for holding the substrate in a substantially horizontal posture with the substrate surface wet with the processing liquid facing upward, and the processing A replacement means for supplying a low surface tension solvent having a lower surface tension than the liquid to the substrate surface and replacing the treatment liquid adhering to the substrate surface with the low surface tension solvent; and a liquid or a treatment liquid having the same composition as the treatment liquid And a liquid with the same main component from the nozzle to the substrate surface on which the low surface tension solvent is attached in a columnar shape, the nozzle is scanned with respect to the substrate surface, thereby forming a paddle-like liquid layer on the substrate surface. And a second liquid layer forming means for forming the substrate, wherein the liquid layer is removed from the substrate surface and the substrate surface is dried.

  According to the second aspect of the invention (substrate processing method and apparatus) configured as described above, even if a fine pattern is formed on the substrate surface, after the low surface tension solvent has entered the pattern gap. By forming a paddle-like liquid layer on the surface of the substrate, the low surface tension solvent is prevented from escaping from the pattern gap to the surface layer portion. Further, by removing the low surface tension solvent in the surface layer portion by forming the liquid layer, it is possible to prevent the substrate surface from being contaminated by particles present in the low surface tension solvent. Furthermore, in order to allow the low surface tension solvent to enter the inside of the pattern gap, it is only necessary to prepare a low surface tension solvent that can replace the treatment liquid adhering to the substrate surface, and the liquid layer is made of a liquid different from the low surface tension solvent. Since it forms, the consumption of the low surface tension solvent required for the process per board | substrate can be suppressed, and cost reduction can be aimed at.

  In addition, according to the present invention, when the paddle-shaped liquid layer is formed, the nozzle is scanned with respect to the substrate surface while supplying the columnar liquid from the nozzle. Can be dispersed. Therefore, it is possible to prevent the liquid from continuing to be supplied only to a specific surface portion on the substrate surface, and the liquid for the low surface tension solvent entering the pattern gap existing in the surface portion to form a liquid layer. Can be suppressed. As a result, it is possible to achieve in-plane uniformity of the drying process while preventing pattern collapse when the substrate surface is dried.

  Here, when forming the paddle-shaped liquid layer, the nozzle may be scanned along a first scanning locus passing through the rotation center position and the edge position of the rotating substrate, You may comprise so that a nozzle may be scanned along the 2nd scanning locus | trajectory which remove | deviates from the rotation center of the board | substrate which is rotating, and passes the center adjacent position and edge position adjacent to this rotation center. Regardless of which configuration is employed, it is possible to prevent the liquid from continuing to be supplied only to a specific surface portion on the substrate surface by dispersing the liquid supply position on the substrate surface. In particular, according to the latter configuration, since the rotational center position deviates from the scanning trajectory of the nozzle, the low surface tension solvent entering the pattern gap located at the center of the substrate forms a liquid layer. It can be reliably suppressed that the liquid is replaced. That is, when the nozzle is scanned along a trajectory passing through the rotation center position, the supply time during which the liquid is directly supplied to the central portion of the substrate tends to be longer than the edge portion of the substrate. That is, because the substrate is rotating, the relative speed with respect to the nozzle is slow at the center of the substrate, and becomes faster toward the edge. Therefore, the amount of DIW supplied directly per unit time in the central portion where the relative speed is low is larger than that in the edge portion. As a result, the low surface tension solvent present inside the pattern gap located at the center of the substrate is more liquid than the low surface tension solvent located inside the pattern gap located at the edge portion. It was easy to replace. On the other hand, as in the latter configuration, it is possible to avoid supplying the liquid directly to the center of the substrate by removing the rotation center position of the substrate surface from the scanning trajectory of the nozzle. In addition, by scanning the nozzle along a trajectory that passes through the center adjacent position adjacent to the rotation center of the substrate, the liquid supplied to the substrate surface is also circulated to the center of the substrate to form a liquid layer on the substrate surface. can do. Therefore, pattern collapse at the center of the substrate can be reliably prevented, and the in-plane uniformity of the drying process can be effectively achieved.

  The “low surface tension solvent” used in the present invention includes a liquid having the same composition as the treatment liquid or a liquid having the same main component as the treatment liquid, and an organic solvent component that dissolves in the liquid to lower the surface tension. May be used, or a 100% organic solvent component may be used. By using the mixed solution, it is possible to suppress the consumption amount of the organic solvent component as compared with the case where 100% of the organic solvent component is supplied to the substrate surface. Moreover, it may replace with the solvent containing an organic solvent component as a low surface tension solvent, and may use the solvent which essentially contains surfactant. Here, an alcohol-based organic solvent can be used as the “organic solvent component”. As the alcohol-based organic solvent, isopropyl alcohol, ethyl alcohol, or methyl alcohol can be used from the viewpoints of safety, cost, and the like, and isopropyl alcohol (IPA) is particularly preferable.

  According to this invention, after the low surface tension solvent has entered the pattern gap, the low surface tension solvent escapes from the pattern gap to the surface layer portion by forming a paddle-like liquid layer on the substrate surface. It is suppressed. Further, by removing the low surface tension solvent in the surface layer portion, it is possible to prevent the substrate surface from being contaminated by particles present in the low surface tension solvent. Furthermore, in order to allow the low surface tension solvent to enter the inside of the pattern gap, it is only necessary to prepare a low surface tension solvent that can replace the treatment liquid adhering to the substrate surface, and the liquid layer is made of a liquid different from the low surface tension solvent. Since it forms, the consumption of a low surface tension solvent can be suppressed and cost reduction can be aimed at. In addition, when forming the liquid layer, a low surface tension solvent within the pattern gap is obtained by using a mist-like liquid or by scanning the nozzle with respect to the substrate surface while supplying the liquid in a columnar shape from the nozzle. The replacement from liquid to liquid can be suppressed and the drying process can be performed satisfactorily.

<First Embodiment>
FIG. 1 is a diagram showing a first embodiment of a substrate processing apparatus according to the present invention. FIG. 2 is a block diagram showing a main control configuration of the substrate processing apparatus of FIG. This substrate processing apparatus is a single-wafer type substrate processing apparatus used for a cleaning process for removing unnecessary substances attached to the surface Wf of a substrate W such as a semiconductor wafer. More specifically, the substrate surface Wf is subjected to a chemical treatment with a chemical solution such as hydrofluoric acid and a rinse treatment with a rinse solution such as DIW (deionized water), and then the substrate surface Wf wet with the rinse solution is dried. It is. In this embodiment, the substrate surface Wf refers to a pattern formation surface on which a device pattern is formed.

  The substrate processing apparatus includes a spin chuck 1 that rotates while holding the substrate W in a substantially horizontal position with the substrate surface Wf facing upward, a chemical nozzle 3 that supplies a chemical solution and a rinse solution from above the substrate W, and A rinse nozzle 5, a gas nozzle 6 that supplies nitrogen gas from above the substrate W, and a mist supply nozzle 9 that supplies mist-like DIW to the substrate surface Wf from above the substrate W are provided. Here, the rinse nozzle 5 can selectively supply the substrate W with DIW and a mixed liquid (low surface tension solvent) in which the organic solvent component that dissolves in the DIW and lowers the surface tension is mixed. Yes.

  The spin chuck 1 has a rotation support shaft 11 connected to a rotation shaft of a chuck rotation mechanism 13 including a motor, and can rotate about a vertical axis around a rotation center A0 by driving the chuck rotation mechanism 13. A disc-shaped spin base 15 is integrally connected to the upper end portion of the rotation spindle 11 by a fastening component such as a screw. Therefore, the spin base 15 rotates around the vertical axis by driving the chuck rotating mechanism 13 in accordance with an operation command from the control unit 4 that controls the entire apparatus.

  Near the peripheral edge of the spin base 15, a plurality of chuck pins 17 for holding the peripheral edge of the substrate W are provided upright. Three or more chuck pins 17 may be provided to securely hold the circular substrate W, and are arranged at equiangular intervals along the peripheral edge of the spin base 15. Each of the chuck pins 17 includes a substrate support portion that supports the peripheral portion of the substrate W from below, and a substrate holding portion that holds the substrate W by pressing the outer peripheral end surface of the substrate W supported by the substrate support portion. Yes. Each chuck pin 17 is configured to be switchable between a pressing state in which the substrate holding portion presses the outer peripheral end surface of the substrate W and a released state in which the substrate holding portion is separated from the outer peripheral end surface of the substrate W.

  When the substrate W is delivered to the spin base 15, the plurality of chuck pins 17 are released, and when the substrate W is cleaned, the plurality of chuck pins 17 are pressed. To do. By setting the pressed state, the plurality of chuck pins 17 can grip the peripheral edge of the substrate W and hold the substrate W in a substantially horizontal posture at a predetermined interval from the spin base 15. As a result, the substrate W is supported with its front surface (pattern forming surface) Wf facing upward and the back surface Wb facing downward. Thus, in this embodiment, the chuck pin 17 functions as the “substrate holding means” of the present invention. The substrate holding means is not limited to the chuck pins 17, and a vacuum chuck that supports the substrate W by sucking the substrate back surface Wb may be used.

  The chemical nozzle 3 is connected to a chemical supply source via an opening / closing valve 31. For this reason, when the opening / closing valve 31 is opened and closed based on a control command from the control unit 4, the chemical solution is pumped from the chemical solution supply source toward the chemical solution nozzle 3, and the chemical solution is discharged from the chemical solution nozzle 3. Note that hydrofluoric acid or BHF (buffered hydrofluoric acid) or the like is used as the chemical solution. Further, a nozzle moving mechanism 33 (FIG. 2) is connected to the chemical liquid nozzle 3, and the chemical liquid nozzle 3 is rotated by rotating the substrate W by driving the nozzle moving mechanism 33 in accordance with an operation command from the control unit 4. It is possible to reciprocate between a discharge position above the center A0 and a standby position retracted laterally from the discharge position. Similarly, a nozzle moving mechanism 53 (FIG. 2) is also connected to the rinsing nozzle 5, and the rinsing nozzle 5 is attached to the substrate W by driving the nozzle moving mechanism 53 in accordance with an operation command from the control unit 4. It can be reciprocated between a discharge position above the rotation center A0 and a standby position retracted laterally from the discharge position.

  A liquid supply unit 7 for selectively supplying DIW and a mixed liquid (DIW + organic solvent component) to the rinse nozzle 5 is connected to the rinse nozzle 5. The liquid supply unit 7 includes a cabinet part 70 for generating a mixed liquid, and the liquid mixture generated in the cabinet part 70 can be pumped to the rinse nozzle 5. The liquid supply unit 7 can also pump DIW directly to the rinse nozzle 5. As the organic solvent component, a substance that dissolves in DIW (surface tension: 72 mN / m) and lowers the surface tension, for example, isopropyl alcohol (surface tension: 21 to 23 mN / m) is used. The organic solvent component is not limited to isopropyl alcohol (IPA), and various organic solvent components such as ethyl alcohol and methyl alcohol may be used. The organic solvent component is not limited to a liquid, and various alcohol vapors may be dissolved in DIW as an organic solvent component to generate a mixed solution.

  The cabinet unit 70 includes a storage tank 72 that stores a mixed liquid of DIW and IPA. One end of a DIW introduction pipe 73 for supplying DIW into the storage tank 72 is taken into the storage tank 72, and the other end is a DIW supply source constituted by a factory utility or the like via an opening / closing valve 73a. It is connected to the. Further, a flow meter 73b is interposed in the course of the DIW introduction pipe 73, and the flow meter 73b measures the flow rate of DIW introduced into the storage tank 72 from the DIW supply source. Based on the flow rate measured by the flow meter 73b, the control unit 4 controls the opening / closing valve 73a so that the flow rate of DIW flowing through the DIW introduction pipe 73 becomes a target flow rate (target value).

  Similarly, one end of the IPA introduction pipe 74 for supplying the IPA liquid into the storage tank 72 is taken into the storage tank 72, and the other end is connected to the IPA supply source via the opening / closing valve 74a. Yes. Further, a flow meter 74b is provided in the middle of the route of the IPA introduction pipe 74, and the flow meter 74b measures the flow rate of the IPA liquid introduced into the storage tank 72 from the IPA supply source. Then, the control unit 4 controls opening / closing of the opening / closing valve 74a based on the flow rate measured by the flow meter 74b so that the flow rate of the IPA liquid flowing through the IPA introduction pipe 74 becomes a target flow rate (target value).

  In this embodiment, the volume percentage of IPA in the liquid mixture (hereinafter referred to as “IPA concentration”) is introduced into the storage tank 72 so that a predetermined value belonging to the range of 50% or less, for example, the IPA concentration is 10%. Adjust the IPA liquid and DIW flow rates. By setting the IPA concentration in this way, it is possible to efficiently prevent the collapse of the pattern formed on the substrate surface Wf while suppressing the consumption of IPA as will be described later. In addition, it is possible to simplify the countermeasures against exposure of the device to IPA compared to 100% IPA.

  The other end of the mixed liquid supply pipe 75 whose one end is connected to the mixing valve 71 is inserted into the storage tank 72, and the mixed liquid stored in the storage tank 72 is supplied to the mixing valve 71 via the opening / closing valve 76. It is configured to be possible. In the mixed liquid supply pipe 75, the liquid mixture stored in the storage tank 72 is sent to the mixed liquid supply pipe 75, and the temperature of the mixed liquid sent to the mixed liquid supply pipe 75 is adjusted by the quantitative pump 77. A temperature controller 78 and a filter 79 for removing foreign substances in the mixed liquid are provided. Furthermore, a concentration meter 80 for monitoring the IPA concentration is interposed in the mixed solution supply pipe 75.

  In addition, one end of a mixed liquid circulation pipe 81 is connected to the mixed liquid supply pipe 75 between the open / close valve 76 and the concentration meter 80 while the other end of the mixed liquid circulation pipe 81 is connected to the storage tank 72. ing. An opening / closing valve 82 is interposed in the mixed liquid circulation pipe 81. During operation of the apparatus, the metering pump 77 and the temperature controller 78 are always driven, and while the liquid mixture is not supplied to the substrate W, the on-off valve 76 is closed and the on-off valve 82 is opened. Thereby, the liquid mixture sent out from the storage tank 72 by the metering pump 77 is returned to the storage tank 72 through the liquid mixture circulation pipe 81. That is, while the mixed liquid is not supplied to the substrate W, the mixed liquid circulates through a circulation path including the storage tank 72, the mixed liquid supply pipe 75, and the mixed liquid circulation pipe 81. On the other hand, when it is time to supply the mixed liquid to the substrate W, the open / close valve 76 is opened and the open / close valve 82 is closed. As a result, the liquid mixture fed from the storage tank 72 is supplied to the mixing valve 71. Further, the mixing valve 71 is connected to the rinse nozzle 5, and the mixed liquid supplied to the mixing valve 71 is discharged from the rinse nozzle 5 toward the substrate W. As described above, while the mixed liquid is not supplied to the substrate W, the mixed liquid is circulated, whereby the DIW and IPA are stirred, and the DIW and IPA can be sufficiently mixed. In addition, after the opening / closing valve 76 is opened, the liquid mixture that has been adjusted to a predetermined temperature and from which foreign matter has been removed can be quickly supplied to the rinse nozzle 5.

  One end of the DIW supply pipe 83 is branched and connected to the DIW introduction pipe 73 on the upstream side (DIW supply source side) of the opening / closing valve 73a, and the other end of the DIW supply pipe 83 is connected to the mixing valve 71. An open / close valve 84 is interposed in the DIW supply pipe 83. According to such a configuration, when the opening and closing valves 76 and 84 are controlled to open and close according to the control command of the control unit 4, DIW and the mixed liquid (IPA + DIW) are selectively supplied to the rinse nozzle 5. That is, by closing the open / close valve 76 and opening the open / close valve 84, DIW is supplied to the rinse nozzle 5 via the mixing valve 71. On the other hand, by opening the opening / closing valve 76 and closing the opening / closing valve 84, the liquid mixture is supplied to the rinse nozzle 5 via the mixing valve 71.

  A gas nozzle 6 is disposed above the spin chuck 1. The gas nozzle 6 is connected to a gas supply source through an open / close valve 61. For this reason, when the opening / closing valve 61 is opened based on a control command from the control unit 4, nitrogen gas is pumped from the gas supply source toward the gas nozzle 6, and nitrogen gas is discharged from the gas nozzle 6. Further, the gas nozzle 6 is connected to a nozzle moving mechanism 63 (FIG. 2), and the nozzle moving mechanism 63 is driven in accordance with an operation command from the control unit 4 so that the gas nozzle 6 is moved to the rotation center A0 of the substrate W. It can be reciprocated between the upper discharge position and the standby position retracted to the side from the discharge position. In this embodiment, nitrogen gas is supplied from a gas supply source, but air, other inert gas, or the like may be supplied.

  Further, a mist supply nozzle 9 is disposed above the spin chuck 1 in order to form a paddle-like liquid layer of DIW on the substrate surface Wf, as will be described later. The mist supply nozzle 9 is connected to a DIW supply source via an opening / closing valve 91. When DIW is pumped from the DIW supply source to the mist supply nozzle 9 by opening the opening / closing valve 91, the substrate surface Wf is transferred from the mist supply nozzle 9 to the substrate surface Wf. A mist-like DIW is discharged toward Further, the mist supply nozzle 9 is connected to a nozzle moving mechanism 93 (FIG. 2), and the nozzle moving mechanism 93 is driven in accordance with an operation command from the control unit 4 so that the mist supply nozzle 9 is attached to the substrate W. It can be reciprocated between a discharge position above the rotation center A0 and a standby position retracted laterally from the discharge position. The mist supply nozzle 9 discharges the mist-like DIW toward the substrate surface Wf while being fixedly arranged at the discharge position, so that the mist-like DIW can be supplied to the entire surface of the substrate surface Wf. That is, the mist-like DIW discharge angle range is set so that the mist-like DIW from the mist supply nozzle 9 reaches the entire surface of the substrate surface Wf. Thus, in this embodiment, the mist supply nozzle 9 functions as the “fixed nozzle” of the present invention.

  Next, the operation of the substrate processing apparatus configured as described above will be described in detail with reference to FIGS. FIG. 3 is a flowchart showing the operation of the substrate processing apparatus of FIG. FIG. 4 is a schematic diagram showing the operation of the substrate processing apparatus of FIG. When an unprocessed substrate W is carried into the substrate processing apparatus by a substrate transfer means (not shown) (step S1), the control unit 4 controls each part of the apparatus to perform a cleaning process (chemical solution processing + (Rinsing process + replacement process + liquid layer forming process + drying process). Here, a fine pattern made of, for example, poly-Si is formed on the substrate surface Wf. Therefore, in this embodiment, the substrate W is carried into the apparatus with the substrate surface Wf facing upward and is held by the spin chuck 1.

  Subsequently, a chemical solution process is performed on the substrate W. That is, the chemical nozzle 3 is moved to the discharge position, and the substrate W held by the spin chuck 1 is rotated at a predetermined rotation speed (for example, 500 rpm) by driving the chuck rotating mechanism 13 (step S2). Subsequently, when hydrofluoric acid is supplied as a chemical liquid from the chemical liquid nozzle 3 to the substrate surface Wf, the hydrofluoric acid is spread by a centrifugal force, and the entire substrate surface Wf is subjected to a chemical liquid treatment with hydrofluoric acid (step S3).

  When this chemical processing is completed, the chemical nozzle 3 is moved to the standby position. Then, a rinsing process is performed on the substrate W. That is, the rinse nozzle 5 is moved to the discharge position, and the rinse liquid (DIW) is supplied from the rinse nozzle 5 to the surface Wf of the substrate W rotating. Thereby, the rinse liquid is spread by the centrifugal force, and the entire substrate surface Wf is rinsed (step S4). As a result, hydrofluoric acid remaining on the substrate surface Wf is removed from the substrate surface Wf by the rinse liquid. The rotation speed of the substrate W during the rinsing process is set to 30 to 1000 rpm, for example.

  When the rinsing process for a predetermined time is completed, the control unit 4 discharges the mixed liquid (IPA + DIW) from the rinsing nozzle 5 in place of the rinsing liquid while continuing to rotate the substrate W. Here, in the cabinet section 70, a mixed liquid in which the IPA concentration in the mixed liquid is adjusted to, for example, 10% is generated in advance, and the mixed liquid is discharged from the rinse nozzle 5 toward the substrate surface Wf. The The rotation speed of the substrate W is set to a first rotation speed V1 that is relatively high (for example, 500 rpm or more). In this embodiment, the substrate W is rotated at 1000 rpm as the first rotation speed V1. For this reason, a relatively large centrifugal force acts on the liquid mixture supplied to the substrate surface Wf. As a result, the liquid mixture on the substrate surface Wf flows vigorously and enters the pattern gap. As a result, for example, the state shown in FIG. 4A is changed to the state shown in FIG. 4B, and the rinsing liquid (DIW) adhering to the gap of the fine pattern FP is surely replaced with the mixed liquid (step S5; replacement). Process). Thus, in this embodiment, the rinse nozzle 5 functions as the “replacement means” of the present invention.

  Subsequently, by forming a paddle-like liquid layer on the substrate surface Wf, the mixed liquid entering the pattern gap is prevented from flowing out from the pattern gap to the surface layer portion. Thereby, collapse of the pattern can be effectively prevented in the drying process described later. That is, the pattern collapse is caused by the patterns being attracted by the negative pressure generated in the pattern gap during the drying process. The magnitude of the negative pressure generated in the pattern gap depends on the surface tension of the liquid existing in the pattern gap, and increases as the surface tension of the liquid increases. Therefore, pattern collapse can be effectively prevented by allowing a mixed liquid (low surface tension solvent) having a lower surface tension than the rinse liquid to enter the pattern gap.

  Here, when the paddle-like liquid layer is formed using the mixed liquid, the following problems may occur. That is, the liquid mixture contains particles such as foreign matters present in the liquid mixture and non-volatile components in the IPA. When a liquid layer is formed by the liquid mixture on the substrate surface Wf, the substrate surface Wf is caused by the particles. It was sometimes contaminated. In addition, in order to form a paddle-like liquid layer on the substrate surface Wf using the mixed liquid, a relatively large amount of IPA is required, and the consumption of IPA increases.

  Therefore, in this embodiment, the liquid layer forming process is executed using DIW after the replacement process with the mixed liquid. First, the control unit 4 decelerates the rotation speed of the substrate W to a second rotation speed V2 that is lower than the first rotation speed V1 (for example, 50 rpm or less). Subsequently, by supplying DIW to the substrate surface Wf, a paddle-like liquid layer made of DIW is formed on the entire surface of the substrate surface Wf. In this liquid layer forming process, since the rotation speed of the substrate W is set to a relatively low speed, the replacement of the mixed liquid existing in the gaps of the fine pattern FP due to the flow of DIW with DIW is suppressed. That is, it is possible to prevent the liquid mixture entering the gap of the fine pattern FP from flowing out from the gap to the surface layer portion. Therefore, only the liquid mixture in the surface layer portion is replaced with DIW while leaving the liquid mixture present in the gaps of the fine pattern FP, and is removed from the substrate surface Wf. Here, simply considering the formation of a paddle-like liquid layer of DIW on the substrate surface Wf, a nozzle is fixedly disposed above the substrate surface Wf, and DIW is discharged from the nozzle in a columnar shape and supplied to the substrate surface Wf. It is conceivable to do this (FIG. 5).

  FIG. 5 is a diagram showing a comparative example when the liquid layer forming process is executed. After the replacement process, the control unit 4 decelerates the rotation speed of the substrate W to the second rotation speed V2 and discharges DIW in a columnar shape from the rinse nozzle 5 fixedly disposed at the discharge position above the substrate surface Wf. As a result, DIW is supplied to the central portion of the substrate surface Wf, and the DIW expands in the direction of the edge of the substrate W. As a result, a paddle-like liquid layer 21 made of DIW is formed on the entire surface of the substrate surface Wf (FIG. 5A). However, when DIW is supplied to the substrate surface Wf in this manner, the flow rate of DIW at the surface portion (direct supply portion) DR that is located directly below the rinse nozzle 5 and receives DIW supply directly from the rinse nozzle 5 is As the DIW spreads from the direct supply part DR, the flow rate of DIW becomes larger than the DIW flow rate at the surface part (indirect supply part) that receives the DIW supply indirectly. That is, the flow rate of DIW in the direct supply region DR becomes larger than the flow rate of DIW in the indirect supply region, although the substrate W is rotated at a low speed. As a result, the liquid mixture that has entered the gap between the fine patterns FP directly located in the supply region DR is replaced with DIW (FIG. 5B).

  On the other hand, in this embodiment, in order to solve the above-described problem, a paddle-like liquid layer made of DIW is formed on the substrate surface Wf as shown in FIG.

  FIG. 6 is a diagram showing an example when the liquid layer forming process is executed. After the replacement process, the control unit 4 decelerates the rotation speed of the substrate W to the second rotation speed V2, and fixes and arranges the mist supply nozzle 9 at the discharge position. Then, mist-like DIW is discharged from the mist supply nozzle 9 toward the entire surface of the substrate surface Wf, and a paddle-like liquid layer 21 made of DIW is formed on the entire surface of the substrate surface Wf (step S6; liquid layer forming step). By supplying DIW to the substrate surface Wf in such a mist form, the flow rate of DIW reaching each part of the substrate surface Wf can be made relatively small. For this reason, it can suppress that the liquid mixture which entered the inside of the space | interval of the fine pattern FP in each part of the board | substrate surface Wf is replaced with DIW. As a result, as shown in FIG. 4C, only the liquid mixture in the surface layer portion is replaced with DIW while leaving the liquid mixture present in the gaps of the fine pattern FP. In the liquid layer forming process, the rotation of the substrate W is not essential, and the liquid layer 21 may be formed in a state where the rotation of the substrate W is stopped. Thus, in this embodiment, the mist supply nozzle 9 functions as the “first liquid layer forming means” of the present invention.

  When the liquid layer 21 is thus formed on the substrate surface Wf (FIG. 7A), the mist supply nozzle 9 is moved to the standby position. Further, following the liquid layer forming process, the substrate W is rotated at the second rotation speed V2 or is stopped. And the discharge process of the liquid layer 21 from the substrate surface Wf by nitrogen gas is performed. That is, the gas nozzle 6 is moved to the discharge position, and nitrogen gas is blown from the gas nozzle 6 toward the center of the surface of the substrate W. Then, as shown in FIG. 7B, the liquid located in the central portion of the liquid layer 21 is pushed away from the radial direction of the substrate W by the nitrogen gas blown from the gas nozzle 6 to the substrate surface Wf, and the center of the liquid layer 21 A hole 22 is formed in the portion, and the surface portion is dried. The mixed liquid remains in the pattern gap. Then, nitrogen gas is continuously blown to the center of the surface of the substrate W, so that the holes 22 formed earlier are formed in the direction of the edge of the substrate W (the left-right direction in FIG. 7). The liquid located on the center side of the liquid layer 21 is gradually pushed from the center side to the substrate edge side, and the drying area is expanded (step S7). Thereby, most of the liquid constituting the liquid layer 21 is removed from the substrate surface Wf except for the mixed liquid adhering to the inside of the pattern gap.

  In this way, by performing the pre-drying process, the liquid constituting the liquid layer 21 remains in the form of droplets at the center of the surface of the substrate W during the drying process described later, and becomes a streak-like particle. It is possible to prevent a watermark from occurring in Wf. That is, when the substrate W is rotated to remove the liquid layer 21 adhering to the substrate surface Wf and dry (spin dry) the substrate W, the centrifugal force acting on the liquid constituting the liquid layer 21 is applied to the substrate W. The liquid located at the center of the surface is smaller and is dried from the edge of the surface of the substrate W. At this time, a droplet remains from the center of the surface of the substrate W to the periphery thereof, and the droplet may run in the direction of the edge of the substrate W, and a watermark may be formed on the movement trace of the droplet. . On the other hand, according to this embodiment, the liquid located in the center of the surface of the substrate W is formed by forming the hole 22 in the center of the liquid layer 21 in advance and expanding the hole 22 before the drying step. Therefore, the generation of the watermark can be surely prevented.

  When the drying pretreatment process is completed, the control unit 4 accelerates the rotation speed of the substrate W to rotate the substrate W at a high speed (for example, 3000 rpm). Thereby, the liquid component remaining and adhered to the substrate surface Wf is shaken off, and the drying process (spin drying) of the substrate W is executed (step S8; drying process). At this time, the mixed solution has entered the pattern gap. Therefore, it is possible to improve the throughput by reducing the drying time while preventing the pattern collapse. In addition, by shortening the drying time in this way, it is possible to reduce the elution of the oxidizable substance of the liquid component adhering to the substrate W, and to more effectively suppress the generation of the watermark. When the drying process of the substrate W is completed, the control unit 4 controls the chuck rotating mechanism 13 to stop the rotation of the substrate W (step S9). Thereafter, the substrate transfer means carries the processed substrate W out of the apparatus, and a series of cleaning processes for one substrate W is completed (step S10).

  As described above, according to this embodiment, after the rinsing process, the mixed liquid (low surface tension solvent) having a surface tension lower than that of the rinsing liquid (DIW) is allowed to enter the pattern gap, and then on the substrate surface Wf. By forming the liquid layer 21 on the surface, the liquid mixture entering the pattern gap is prevented from coming out from the pattern gap to the surface layer portion. For this reason, pattern collapse at the time of substrate drying can be prevented. Further, the liquid mixture in the surface layer portion is removed from the substrate surface Wf while the liquid mixture 21 is formed so that the liquid mixture is substantially left in the pattern gap. Therefore, it is possible to prevent the substrate surface Wf from being contaminated by particles present in the mixed liquid. Further, unlike the mixed liquid (IPA + DIW), the rinsing process is performed with a rinsing liquid composed of only DIW, while the replacement process may be performed by preparing an IPA that replaces the rinsing liquid adhering to the substrate surface Wf with the mixed liquid. Further, the liquid layer 21 is formed only by DIW without using IPA. Therefore, it is possible to reduce the cost by suppressing the consumption of IPA required for processing per substrate.

  In addition, according to this embodiment, since the mist-like DIW is used when forming the liquid layer 21, it is possible to prevent the mixed liquid entering the pattern gap at each part of the substrate surface Wf from being replaced by DIW. can do. Therefore, since the substrate surface Wf is dried from the state in which the mixed liquid remains in the pattern gap, it is possible to effectively prevent pattern collapse and dry the substrate surface Wf satisfactorily. Further, since the mist-like DIW is supplied from the mist supply nozzle 9 to the substrate surface Wf with the mist supply nozzle 9 fixedly disposed above the substrate surface Wf, the nozzle (mist supply nozzle 9) is used during the liquid layer forming process. It is not necessary to control the drive.

  Further, according to this embodiment, since the IPA concentration in the mixed solution is set to 50% or less, the pattern collapse can be efficiently prevented while suppressing the IPA consumption as described below. FIG. 8 is a graph showing the relationship between the IPA concentration and the surface tension γ. The horizontal axis shown in FIG. 8 represents the IPA concentration. When the IPA concentration is 0 (vol%), DIW is simple, and when the IPA concentration is 100 (vol%), the IPA liquid is simple. Yes. The surface tension γ is measured by the hanging drop method (pendant drop method) using LCD-400S manufactured by Kyowa Interface Science Co., Ltd. As is clear from FIG. 8, when the IPA mixture amount to DIW is increased, the surface tension γ of the mixed solution rapidly decreases as the IPA mixture amount to DIW increases until the IPA concentration is around 10%. I can see that When the IPA concentration is 50% or more, it can be seen that the surface tension of the mixed liquid is not greatly reduced, and the surface tension is almost equal to that of the IPA liquid alone. Therefore, even if the IPA concentration is higher than 50%, no great reduction is observed in the surface tension of the mixed solution, and no significant reduction in the force that causes pattern collapse is expected. That is, the IPA consumption only increases, and no significant improvement can be expected with respect to the pattern collapse prevention effect. Therefore, by setting the IPA concentration to 50% or less, it is possible to efficiently prevent pattern collapse while suppressing the consumption of IPA. Further, from this point of view, the IPA concentration is preferably 5% to 35%, more preferably 5% to 10%.

Second Embodiment
FIG. 9 is a view showing the operation of the liquid layer forming process of the substrate processing apparatus according to the second embodiment of the present invention. Here, FIG. 4A is a side view and FIG. 4B is a plan view. The substrate processing apparatus according to the second embodiment is greatly different from the first embodiment in that when forming a liquid layer, the nozzle is scanned with respect to the substrate surface Wf while DIW is ejected from the nozzle in a columnar shape. Is a point. Other configurations and operations are basically the same as those in the first embodiment, and therefore, differences will be mainly described here.

  In this embodiment, the DIW nozzle 5A is attached to one end of a nozzle arm 51 extending in the horizontal direction. A nozzle moving mechanism 53 </ b> A is connected to the other end of the nozzle arm 51. Then, the nozzle moving mechanism 53A is actuated in accordance with an operation command from the control unit 4, whereby the nozzle arm 51 is driven to swing around a predetermined rotation axis. When the nozzle arm 51 is swung by the operation of the nozzle moving mechanism 53A, the DIW nozzle 5A moves along the scanning locus T1 (corresponding to the “first scanning locus” of the present invention) in a state of facing the substrate surface Wf. This scanning locus T1 is a locus from the rotation center position Ca toward the edge position Ea. Here, the rotation center position Ca of the substrate W is located above the substrate surface Wf and above the rotation center A0 of the substrate W, and the edge position Ea is located above the outer peripheral edge of the substrate W.

  The DIW nozzle 5A is connected to a DIW supply source (not shown). When the DIW nozzle 5A is disposed above the substrate surface Wf and DIW is supplied from the DIW supply source to the DIW nozzle 5A, DIW is discharged in a column shape from the DIW nozzle 5A toward the substrate surface Wf. When the DIW nozzle 5A is moved along the scanning trajectory T1 while the control unit 4 rotates the substrate W in a state where DIW is discharged from the DIW nozzle 5A in a column shape, DIW is supplied to each part of the substrate surface Wf. Is done.

  In the substrate processing apparatus configured as described above, the liquid layer forming process is executed as follows after the chemical process, the rinse process, and the replacement process using the mixed liquid, as in the first embodiment. That is, the control unit 4 positions the DIW nozzle 5A at the rotation center position Ca. Then, while rotating the substrate W (rotational speed: V2), the DIW nozzle 5A is gradually moved toward the edge position Ea while DIW is ejected from the DIW nozzle 5A toward the substrate surface Wf in a column shape. As a result, a liquid pool is formed by DIW at the center of the substrate surface Wf, and the liquid pool expands in the direction of the edge of the substrate W as the DIW supply position moves radially outward. As a result, the liquid mixture in the surface layer portion is removed from the substrate surface Wf while leaving the liquid mixture present inside the pattern gap, and a paddle-like liquid layer 21 of DIW is formed on the entire surface of the substrate surface Wf (liquid layer formation). Process). Thus, in this embodiment, the DIW nozzle 5A and the nozzle moving mechanism 53A correspond to the “second liquid layer forming means” of the present invention. In this embodiment, the DIW nozzle 5A is used during the liquid layer forming process. However, the DIW is supplied from the rinse nozzle 5 that can selectively supply DIW and the mixed liquid, and the rinse nozzle 5 is applied to the substrate surface Wf. Alternatively, scanning may be performed.

  As described above, according to this embodiment, the liquid layer 21 is formed on the substrate surface Wf, so that the liquid mixture entering the pattern gap can be transferred from the pattern gap to the surface layer portion as in the first embodiment. It is suppressed from coming out. Further, by removing the liquid mixture in the surface layer portion by forming the liquid layer 21, it is possible to prevent the substrate surface Wf from being contaminated by particles present in the liquid mixture. Furthermore, in the replacement process, it is sufficient to prepare a liquid mixture that only replaces the rinsing liquid adhering to the substrate surface Wf. In the liquid layer formation process, the liquid layer 21 is formed by DIW, so that the consumption of IPA is suppressed. Thus, cost reduction can be achieved.

  Moreover, according to this embodiment, when the liquid layer 21 is formed, the DIW nozzle 5A is scanned with respect to the substrate surface Wf, so that the DIW supply sites on the substrate surface Wf can be dispersed. Therefore, it is possible to prevent the DIW from being continuously supplied only to a specific surface portion of the substrate surface Wf, and to prevent the mixed liquid entering the pattern gap existing in the surface portion from being replaced with DIW. . As a result, the in-plane uniformity of the drying process can be achieved while preventing pattern collapse during the drying process.

<Third Embodiment>
FIG. 10 is a plan view showing the operation of the liquid layer forming process of the substrate processing apparatus according to the third embodiment of the present invention. The substrate processing apparatus according to the third embodiment is greatly different from the second embodiment in that the rotation center position (above the rotation center A0) deviates from the scanning locus of the DIW nozzle 5A. Since other configurations and operations are basically the same as those of the second embodiment, the same reference numerals are given here and description thereof is omitted.

  In this embodiment, the DIW nozzle 5A moves along the scanning locus T2 (corresponding to the “second scanning locus” of the present invention) while facing the substrate surface Wf. This scanning trajectory T2 is a trajectory from the center adjacent position Cb deviating from the rotation center A0 toward the edge position Eb. Here, the center adjacent position Cb of the substrate W is set to a position above the substrate surface Wf and adjacent to the rotation center position. The edge position Eb is located above the outer peripheral edge of the substrate W. Then, after the replacement process, when the control unit 4 positions the DIW nozzle 5A at the center adjacent position Cb, the DIW nozzle 5A is rotated in a columnar shape toward the substrate surface Wf while rotating the substrate W, and the scanning locus T2 is reached. Then, the DIW nozzle 5A is gradually moved toward the edge position Eb.

  Here, when the rocking speed of the nozzle arm 51 is constant, the relative speed with respect to the DIW nozzle 5A is slow at the center of the substrate W, and becomes faster toward the edge. Therefore, when the nozzle is moved along a trajectory passing through the rotation center position, the supply amount of DIW directly supplied per unit time is larger in the central portion where the relative speed is slow than in the edge portion. As a result, the mixed liquid existing inside the pattern gap located at the center of the substrate W is more easily replaced with DIW than the mixed liquid existing inside the pattern gap located at the edge.

  On the other hand, according to this embodiment, since the rotation center position of the substrate surface Wf (above the rotation center A0) is deviated from the scanning locus T2, the center Wc of the substrate W including the rotation center A0 is located. It can be avoided that DIW is supplied directly. Moreover, since the substrate W is rotated at a relatively low speed (rotation speed: V2), the DIW nozzle 5A is moved along the locus (scanning locus T2) passing through the center adjacent position Cb adjacent to the rotation center A0. The DIW supplied to the substrate surface Wf can be caused to indirectly enter the central portion Wc of W. Thereby, the liquid layer 21 can be formed on the entire surface of the substrate surface Wf.

  As described above, according to this embodiment, since the DIW nozzle 5A is scanned with respect to the substrate surface Wf, the DIW supply sites on the substrate surface Wf are dispersed in the same manner as in the second embodiment. It is possible to prevent the DIW from continuing to be supplied only to a specific surface portion on the surface Wf. Further, since DIW is prevented from being directly supplied to the central portion of the substrate W, adverse effects caused when DIW is directly supplied to the central portion of the substrate W can be prevented. That is, it is possible to solve the problem that the replacement of the mixed liquid existing in the pattern gap with DIW is more likely to occur at the center portion than at the edge portion. As a result, pattern collapse at the center of the substrate W can be reliably prevented, and the in-plane uniformity of the drying process can be effectively achieved.

<Others>
The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the first embodiment, mist-like DIW is supplied from the mist supply nozzle 9 to the substrate surface Wf with the mist supply nozzle 9 fixed at the discharge position. The mist-like DIW may be supplied to the substrate surface Wf while scanning (4th embodiment).

  FIG. 11 is a side view showing the operation of the liquid layer forming process of the substrate processing apparatus according to the fourth embodiment of the present invention. In this embodiment, the mist supply nozzle 9A is movably disposed along the substrate surface Wf, and the mist supply nozzle 9A can be scanned with respect to the substrate surface Wf by driving the nozzle drive mechanism 93A. The nozzle driving mechanism 93 </ b> A may move the mist supply nozzle 9 </ b> A along a trajectory from an upper position of the center portion of the substrate W toward an upper position of the edge portion of the substrate W, or above the edge portion of the substrate W. The mist supply nozzle 9A may be moved along a trajectory from the position through an upper position of the center portion of the substrate W toward an upper position of another edge portion. Further, the mist supply nozzle 9A may be reciprocated along these trajectories.

  The mist supply nozzle 9A is connected to a DIW supply source. When DIW is pumped from the DIW supply source to the mist supply nozzle 9A, DIW is locally supplied from the mist supply nozzle 9A toward the substrate surface Wf. That is, the supply range in which the mist-like DIW from the mist supply nozzle 9A is supplied to the substrate surface Wf is limited to a partial region of the substrate surface Wf. Therefore, in a state where mist-like DIW is discharged from the mist supply nozzle 9A, the control unit 4 scans the mist supply nozzle 9A with respect to the substrate surface Wf while rotating the substrate W, thereby padding the entire surface of the substrate surface Wf. The liquid layer 21 can be formed. Thus, in this embodiment, the mist supply nozzle 9A functions as the “movable nozzle” of the present invention.

  As described above, according to this embodiment, since the liquid layer 21 is formed on the substrate surface Wf using the mist-like DIW, the mixing entering the pattern gap as in the first embodiment. It is possible to reliably prevent the liquid from being replaced by DIW. Furthermore, since the mist-like DIW is locally supplied to the substrate surface Wf, the mist-like DIW can be prevented from being scattered around the substrate W.

  In the second embodiment, the DIW nozzle 5A is moved from the rotation center position Ca toward the edge position Ea along the scanning locus T1, but the DIW nozzle 5A is reciprocated on the scanning locus T1. Also good. Alternatively, the DIW nozzle 5A may be moved along a trajectory from a predetermined edge position to another edge position through the rotation center position Ca. Similarly, in the third embodiment, the DIW nozzle 5A is moved from the center adjacent position Cb toward the edge position Eb along the scanning trajectory T2, but the DIW nozzle 5A is reciprocated on the scanning trajectory T2. You may let them. Alternatively, the DIW nozzle 5A may be moved along a trajectory from a predetermined edge position to another edge position through the center adjacent position Cb. In short, the liquid layer 21 may be formed on the substrate surface Wf by scanning the substrate surface Wf while discharging DIW from the DIW nozzle 5A.

  In the above embodiment, the liquid layer 21 is formed on the entire surface of the substrate surface Wf in the liquid layer forming step. However, the liquid layer 21 is not necessarily formed on the entire surface of the substrate surface Wf. The liquid layer 21 may be formed on the part. For example, DIW is supplied to the central part of the substrate surface Wf, and a liquid layer (liquid film) 21 of DIW is formed in the central part of the substrate surface Wf (FIG. 12A). In this state, nitrogen gas is blown from the gas nozzle 6 to the center of the substrate surface Wf. Thereby, the liquid layer 21 is formed in an annular shape (FIG. 12B). Subsequently, by blowing nitrogen gas onto the substrate surface Wf, the annular liquid layer 21 is gradually enlarged from the central portion of the substrate surface Wf toward the edge of the substrate W (FIG. 12C). In this way, by gradually moving the DIW liquid layer 21 formed on a part of the substrate surface Wf on the substrate surface Wf, the surface layer is formed over the entire substrate surface while leaving the liquid mixture present in the pattern gap. Only the portion of the mixed liquid is replaced with DIW and removed from the substrate surface Wf.

  Further, in the above embodiment, after the wet process such as the chemical process and the rinse process is performed on the substrate W, the replacement process and the liquid layer forming process are performed on the substrate surface Wf wet with the rinse liquid in the same apparatus as it is. Although the drying process is executed, the process after the replacement process may be performed separately from the wet process. That is, the apparatus for drying the substrate surface Wf wet with the rinse liquid may be configured as a single unit.

  Moreover, in the said embodiment, although the liquid mixture is produced | generated by mixing the liquid (DIW) and organic solvent component (IPA) of the same composition as a process liquid in the cabinet part 70, the production | generation method of a liquid mixture is in this. It is not limited. For example, an organic solvent component may be mixed in-line on a liquid feeding path for feeding the processing liquid toward a nozzle (substitution unit) to generate a mixed liquid. Further, the liquid mixture generating means such as the cabinet section is not limited to being provided in the substrate processing apparatus, and the liquid mixture generated in another apparatus provided separately from the substrate processing apparatus is provided in the substrate processing apparatus. You may supply to the substrate surface Wf via a nozzle.

  Moreover, in the said embodiment, although a liquid mixture (IPA + DIW) is used as a low surface tension solvent, you may use a 100% IPA liquid. Further, a solvent essentially containing a surfactant may be used instead of the solvent containing an organic solvent component such as IPA. Even if a replacement process is performed using such a 100% IPA liquid or a solvent that essentially contains a surfactant, particles adhere to the substrate surface Wf when the substrate is dried by the liquid layer forming process performed after the replacement process. Can be suppressed.

  In the above embodiment, the substrate surface Wf wet with the rinse liquid is dried. However, the present invention is also applied to a substrate processing method and a substrate processing apparatus for drying the substrate surface Wf wet with a treatment liquid other than the rinse liquid. Can be applied.

In the above embodiment, DIW is used as the rinse liquid. However, a liquid containing a component that does not have a chemical cleaning action on the substrate surface Wf such as carbonated water (DIW + CO ₂ ) is used as the rinse liquid. Also good. In this case, a mixture of a liquid (carbonated water) having the same composition as the rinse liquid adhering to the substrate surface Wf and an organic solvent component may be used as the mixed liquid. Further, while carbonated water is used as the rinse liquid, the mixed liquid may be a mixture of DIW, which is the main component of carbonated water, and an organic solvent component. Further, while DIW is used as the rinsing liquid, the mixed liquid may be a mixture of carbonated water and an organic solvent component. In short, a mixture of a liquid adhering to the substrate surface Wf, a liquid having the same main component, and an organic solvent component may be used as the mixed liquid. In addition to DIW and carbonated water, hydrogen water, dilute concentration (for example, about 1 ppm) ammonia water, dilute hydrochloric acid, and the like can be used as the rinse liquid.

  The present invention relates to a semiconductor wafer, a glass substrate for photomask, a glass substrate for liquid crystal display, a glass substrate for plasma display, a substrate for FED (Field Emission Display), a substrate for optical disk, a substrate for magnetic disk, a substrate for magneto-optical disk, etc. The present invention can be applied to a substrate processing method and a substrate processing apparatus for performing a drying process on the entire surface of a substrate including the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Embodiment of the substrate processing apparatus concerning this invention. It is a block diagram which shows the main control structures of the substrate processing apparatus of FIG. It is a flowchart which shows operation | movement of the substrate processing apparatus of FIG. It is a schematic diagram which shows operation | movement of the substrate processing apparatus of FIG. It is a figure which shows the comparative example at the time of performing a liquid layer formation process. It is a figure which shows the Example at the time of performing a liquid layer formation process. It is a schematic diagram which shows operation | movement of the substrate processing apparatus of FIG. It is a graph which shows the relationship between IPA density | concentration and surface tension (gamma). It is a figure which shows operation | movement of the liquid layer formation process of the substrate processing apparatus concerning 2nd Embodiment of this invention. It is a top view which shows operation | movement of the liquid layer formation process of the substrate processing apparatus concerning 3rd Embodiment of this invention. It is a side view which shows operation | movement of the liquid layer formation process of the substrate processing apparatus concerning 4th Embodiment of this invention. It is a figure which shows the deformation | transformation form of the substrate processing apparatus concerning this invention.

Explanation of symbols

5 ... Rinse nozzle (replacement means)
5A ... DIW nozzle (nozzle, second liquid layer forming means)
9: Mist supply nozzle (fixed nozzle, first liquid layer forming means)
9A ... Mist supply nozzle (movable nozzle)
17 ... chuck pin (substrate holding means)
21 ... Liquid layer 53A ... Nozzle moving mechanism (second liquid layer forming means)
T1: Scanning locus (first scanning locus)
T2: Scanning locus (second scanning locus)
W ... Substrate Wf ... Substrate surface

Claims (8)

In the substrate processing method of drying the substrate surface wet with the processing liquid,
A replacement step of supplying a low surface tension solvent having a surface tension lower than that of the treatment liquid to the surface of the substrate held in a substantially horizontal posture to replace the treatment liquid adhering to the substrate surface with the low surface tension solvent. When,
Liquid layer formation in which a liquid having the same composition as the treatment liquid or a liquid having the same main component as the treatment liquid is supplied to the substrate surface after the replacement step to form a paddle-like liquid layer by the liquid on the substrate surface Process,
A drying step of removing the liquid layer from the substrate surface and drying the substrate surface,
In the liquid layer forming step, the liquid is supplied to the substrate surface in a mist form.   The substrate processing method according to claim 1, wherein in the liquid layer forming step, a mist-like liquid is supplied to the substrate surface from a fixed nozzle fixedly disposed above the substrate surface.   In the liquid layer forming step, the movable nozzle is scanned with respect to the substrate surface while a mist-like liquid is locally supplied to the substrate surface from a movable nozzle that is movably disposed along the substrate surface. Item 2. A substrate processing method according to Item 1. In the substrate processing method of drying the substrate surface wet with the processing liquid,
A replacement step of supplying a low surface tension solvent having a surface tension lower than that of the treatment liquid to the surface of the substrate held in a substantially horizontal posture to replace the treatment liquid adhering to the substrate surface with the low surface tension solvent. When,
Liquid layer formation in which a liquid having the same composition as the treatment liquid or a liquid having the same main component as the treatment liquid is supplied to the substrate surface after the replacement step, thereby forming a paddle-like liquid layer on the substrate surface. Process,
A drying step of removing the liquid layer from the substrate surface and drying the substrate surface,
In the liquid layer forming step, the nozzle is scanned with respect to the substrate surface while supplying the liquid in a column shape from the nozzle.   5. The substrate processing method according to claim 4, wherein, in the liquid layer forming step, the nozzle is scanned along a first scanning locus passing through a rotation center position and an edge position of the rotating substrate.   5. The nozzle is scanned along a second scanning locus that deviates from a rotation center of the rotating substrate and is adjacent to the rotation center and passes through an edge position and a center adjacent position in the liquid layer forming step. Substrate processing method. A substrate holding means for holding the substrate in a substantially horizontal posture with the substrate surface wet with the processing liquid facing upward;
A substitution means for supplying a low surface tension solvent having a surface tension lower than that of the treatment liquid to the substrate surface and replacing the treatment liquid adhering to the substrate surface with the low surface tension solvent;
A liquid having the same composition as the processing liquid or a liquid having the same main component as the processing liquid is supplied to the substrate surface to which the low surface tension solvent is adhered in a mist form to form a paddle-like liquid layer by the liquid First liquid layer forming means for forming on the substrate surface,
A substrate processing apparatus, wherein the liquid layer is removed from the substrate surface to dry the substrate surface. A substrate holding means for holding the substrate in a substantially horizontal posture with the substrate surface wet with the processing liquid facing upward;
A substitution means for supplying a low surface tension solvent having a surface tension lower than that of the treatment liquid to the substrate surface and replacing the treatment liquid adhering to the substrate surface with the low surface tension solvent;
While supplying a liquid having the same composition as the treatment liquid or a liquid having the same main component as the treatment liquid from the nozzle to the substrate surface to which the low surface tension solvent is attached in a columnar shape, the nozzle is directed to the substrate surface. And a second liquid layer forming means for forming a paddle-like liquid layer with the liquid on the substrate surface by scanning,
A substrate processing apparatus, wherein the liquid layer is removed from the substrate surface to dry the substrate surface.

Images